<!doctype html>
<html>
    <head>
        <style type="text/css">
            span {
                font: 40px / 1 Courier;
                font-weight: bold;
            }
            .control {
                font: 12px /1 Arial;
            }
        </style>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script>
        <script src="numberAnimate.js"></script>
         <script>
            $(function(){
                var $span = $('span');
                $span.numberAnimate();
                
                $('input[type=text]').keypress(function(e){
                    if(e.which === 13){
                        e.preventDefault();
                        $span.numberAnimate('set', $(this).val());
                    }
                });
            });
        </script>
    </head>
    <body>
        <span>123.00</span> 
        <div class="control">
            Set value to: <input type="text" />
        </div>
    </body>
</html>